Device for controlling gripper shuttle in looms

ABSTRACT

A device for controlling gripper shuttles in weaving looms, particularly looms using rotary shuttle boxes at both sides thereof, by which the gripper shuttles can be reliably braked upon arrival therein and be prevented from undesirable recoil into the shed. Furthermore, their correct position in the shuttle box can be ascertained at the given moment so that they can be displaced into a position suitable for feeding a new weft thread. Two adjusting stops are arranged on the holder transversal to the guideway of the gripper shuttle in each shuttle box at a distance from the guideway making it possible for the gripper shuttle to pass by them. The stops are of equal length in a direction transverse to the guideway and cooperate with one arm of a swingable two-arm friction damper, which is provided with a surface for adjusting and receiving an arrived gripper shuttle; the other arm of said friction damper forms a stop motion feeler upon an incorrect arrival of the gripper shuttle. The friction damper is fastened at a free end of a control level which is swingable in both a perpendicular and longitudinal plane relative to the guideway of a gripper shuttle inside a shuttle box.

United States Patent 1191 Bilek DEVICE FOR CONTROLLING GRIPPER SHUTTLE IN LOOMS [75] Inventor: Jan Bilek, Liberec, Czechoslovakia [73] Assignee: Elitex, Zavody textilniho strojirenstvi generalni reditelstvi, Liberec, Czechoslovakia 22 Filed: Apr. 16, 1974 21 Appl. No.: 461,412

[58] Field of Search 139/122 R, 125, 126, 155, 139/183, 185, 186, 341, 342, 343

[56] References Cited UNITED STATES PATENTS 3,332,452 7/1967 Mzyk et a1. 139/341 3,487,860 l/1970 Svaty et a1. 139/125 3,563,281 2/1971 Pfarrwaller 139/342 Primary Examiner-Henry S. Jaudon 1451 July 22,1975

[5 7] ABSTRACT A device for controlling gripper shuttles in weaving looms, particularly looms using rotary shuttle boxes at both sides thereof, by which the gripper shuttles can be reliably braked upon arrival therein and be prevented from undesirable recoil into the shed. Furthermore, their correct position in the shuttle box can be ascertained at the given moment so that they can be displaced into a position suitable for feeding a new weft thread. Two adjusting stops are arranged on the holder transversal to the guideway of the gripper shuttle in each shuttle box at a distance from the guideway making it possible for the gripper shuttle to pass by them. The stops are of equal length in a direction transverse to the guideway and cooperate with one arm of a swingable two-arm friction damper, which is provided with a surface for adjusting and receiving an arrived gripper shuttle; the other arm of said friction damper forms a stop motion feeler upon an incorrect arrival of the gripper shuttle. The friction damper is fastened at a free end of a control level which is swingable in both a perpendicular and longitudinal plane relative to the guideway of a gripper shuttle inside a shuttle box.

3 Claims, 6 Drawing Figures PATENTED L 2 2 I975 SHEET lLl PATENTEBJUL 22 ms 3 8 95 6 5T SHEET 2 DEVICE FOR CONTROLLING GRIPPER SHUTTLE IN LOOMS This application is related to the coassigned application Rambousek, Ser. No. 460,421 filed Apr. 10, 1974 which is based upon Czechoslovak patent application PV 2775-73 of Apr. 18, I973.

The present invention relates to a device for controlling gripper shuttles in weaving looms, particularly looms using rotary shuttle boxes at both sides thereof, by which the gripper shuttles can be reliably braked upon arrival therein and be prevented from undesirable recoil into the shed. Furthermore, their correct position in the shuttle box can be ascertained at the given moment so that they can be displaced into a position suitable for feeding a new weft thread.

In weaving looms using a gripper shuttle and cut weft thread, particularly those using a single gripper shuttle which turns 180 at its dead center, losses of weft material are caused by excessively long ends of the weft thread extending beyond the fabric selvedge.

Heretofore, it was necessary to make the gripper shuttle leave the shed completely for the purpose of unthreading the inserted weft thread therefrom. The inserted weft thread was thereupon tensioned from the other side of the loom; this however, was inaccurate. Moreover, the projecting weft thread ends unthreaded from said gripper shuttle had different lengths. The said projecting weft thread ends were inserted into the following shed or were cut off.

In order to make the projecting weft thread ends as short as possible, it was attempted to brake the arriving gripper shuttle after it had travelled through a braking path of the shortest possible length. However, with a short braking path, the braking of the gripper shuttle was too hard and caused excessive wear of the braking jaw and the guiding surfaces in the shuttle box, as well as of the gripper shuttle itself.

It would therefore appear advantageous to use a device which would brake the gripper shuttle upon its arrival over a relatively longer braking path in such manner as not to stress it by impacts. However, this means that the gripper shuttle upon its arrival in the shuttle box will overrun the position at which a new weft thread might be introduced into it, and thus it is necessary to return it into said position and simultaneously to check its presence. The said problem is solved by the present invention.

In the device of the invention two adjusting stops are arranged on a holder transversely to the guideway of the gripper shuttle in each shuttle box at a distance from the guideway making it possible for the gripper shuttle to pass by them. The stops are of unequal length in a direction transverse to the guideway and cooperate with one arm of a swingable two-arm friction damper, which is provided with a surface for receiving and ajusting an arrived gripper shuttle. The other arm of said frictional damper forms a stop motion feeler upon an incorrect arrival of the gripper shuttle; the frictional damper is fastened at a free end of a control lever which is swingable in both a perpendicular and longitudinal plane relative to the guideway of a gripper shuttle inside a shuttle box.

Further features and advantages of the present invention are described in the following specification which obviously does not cover all further possible embodiments of the present invention and in the accompanying drawings, in which FIG. 1 is a view in elevation of a loom with devices according to the present invention on both sides thereof;

FIG. 2 is a detailed view on an enlarged scale of the right side of the loom showing the arrangement of the driving mechanism of the control lever of the frictional damper;

FIG. 3 is a detailed view on a still larger scale showing the position of the frictional damper at the right side of the weaving loom as shown in FIG. 2 with the damper prepared to damp the impact of the gripper shuttle arriving from the left, the control lever of the frictional damper being swung out to the extreme right hand position;

FIG. 4 is a detailed view similar to FIG. 3 showing the position of the frictional damper after it has been touched at its upper arm by the edge of the gripper shuttle, the control lever of said frictional damper being still swung out to the right;

FIG. 5 is a detailed view similar to FIG. 3 and 4 showing the position of the frictional damper after it has been displaced to the left by control lever, the frictional damper being supported with its upper arm against the longer adjusting stop on the holder and having displaced the gripper shuttle back into the given threading position by pressure on its front edge; and

FIG. 6 is a plan view of the arrangement of the frictional damper e.g. as shown in FIG. 5, the view showing both adjustment stops of unequal length for the upper arm of the frictional damper and also showing the edge of the gripper shuttle and the space in which said upper arm of the frictional damper can be swung out, on the one hand, in a vertical direction from the guideway of the gripper shuttle in the shuttle box, and, on the other hand, also in the longitudinal direction relative to said guideway.

The following description of the device for controlling the gripper shuttle is mainly directed to the right hand side of the loom, since the devices employed on both sides of the loom are identical.

On the frame 1 of the loom (FIG. 1) there is mounted the main shaft 2, on which a tube 3 is swingably mounted. Tube 3 is the main beam of the slay 5, which is fastened to tube 3 by means of slay arms 6; the tube carries reed 7 and guiding comb 8, which define the path for passing the gripper shuttle 14 from one side of the loom to the other. Both ends of tube 3 end in housings 9, in which there are mounted the mechanisms of the control levers 10 of frictional dampers 11. Stop motion mechanisms 12 are also arranged on housings 9, as well as rotary shuttle boxes 13 for the shuttle gripper l4, and an ejecting mechanism 15 for the gripper shuttle 14, including the trigger mechanism 16 for the ejecting mechanism.

A motor 17 drives the loom through a transmission 18 which includes electromagnetic clutch-brake mechanism 19 connected to shaft 2. When current passes through terminals 20 (which are connected in both the control and monitoring circuits of the loom) the mechanism 19 operates as a clutch. When the current is interrupted in either the controlling or the monitoring circuit in which there is included stop motion mechanism 12, then the mechanism 19 operates as a brake which stops the loom.

In the bottom of housing 9 on the shaft 2 there is mounted disc 21 with a box cam 22 cut in its periphery, the box cam being engaged by a roller 23 on the lower end of the control lever of the friction damper 11. The control lever 10 is swingably mounted for lateral movement on a pin 24 which is mounted stationarily on a swingable transverse carrier 25 mounted by means of pins 26 in the sides of housing 9. The transverse carrier 25 is provided with an arm 27 and a roller 28 which follows the surface of a face cam 29 which is connected to disc 21. The arm 27 of the transverse carrier 25 is pressed towards the surface of cam 29 by a coil tension spring 30. The cam 22 on disc 21 imparts to the upper end of the control lever 10 of frictional damper 11 a motion parallel the the guideway 31 of the gripper shuttle 14 in shuttle box 13 and cam 29 imparts to said control lever 10 via transverse carrier 25 and its arm 27 a motion in a plane perpendicular to said guideway 31 of gripper shuttle 14 in shuttlebox 13. Such motion of control lever 10 are synchronized since cams 22 and 29 are connected. I

On the upper part of housing 9, there is fastened a shuttle box 13 of. a circular shape having a dovetail guideway 31 for the gripper shuttle 14. The shuttle box oscillates through [80". For that purpose, said shuttle box is provided at its rear end e.g. by a toothed pinion (not shown) which is in engagement by e.g. a rack (not shown) performing a reciprocating motion derived from one of the main members of the loom, e.g. from shaft 2. A braking jaw (not shown) passes through the center of shuttle box 13 and opens at the bottom of said guideway 31 ofgripper shuttle 14. The said brakingjaw presses the arrived gripper shuttle 14 against the inclined walls of the dovetail guideway 31 thus performing an efficient braking of the shuttle. The operation of said braking jaw again suitably synchronized with the other mechanism of the loom, including. the motions of the gripper shuttle 14 in the loom.

The cylinder of a shuttle ejecting device is fastened to the upper part of the housing 9. Inside the cylinder of said ejecting device 15 there is mounted a piston having a piston rod 32, which acts with its free end against the rear of edge 33 of the gripper shuttle 14. The piston in cylinder of the ejecting device 15 is acted upon by a pressure fluid; the moment at which the gripper shuttle 14 is to be ejected with an abrupt forward movement back into the shed is determined by a trigger mechanism 16 having a spring loaded tie rod 34 positioned to be acted upon by the upper free end of control lever 10.

Below shuttle box 13, astop motion mechanism 12 is fixed to housing 9. Mechanism 12 substantially consists of a contactless relay of known construction employing the principle that into an induced magnetic flow in the body of said relay there is introduced an armature e.g. a metal flag 35 carried by tie rod 36, which causes a change in oscillation of said electromagnetic flux. Such change of flux influences e.g. a scanner (not shown) connected into the circuit of the electromagnetic clutch-brake mechanism 19.

' On the cylinder of ejecting mechanism 15 there is fastened a holder 37 with at least two adjusting stops 38 and 39 of unequal length. Such stops being arranged transversely to the guideway 31 at a distance which makes it possible for the gripper shuttle 14 to pass through said guideway 31. The two adjusting stops 38 and '39 are independently adjustable along the length of holder 37 and inside its recess 40 by means of adjusting means 41 and 42. The two adjusting stops 38 and 39 cooperate with the upper arm of the frictional damper 11 in a manner explained below.

Frictional damper 11 is made in the form of an angular two-arm or bellcrank lever and is fastened at the upper free end of control lever 10 approximately at the center of damper 11 by means of an adjusting screw 43 and a friction washer 44. The frictional damper 11 is advantageously made of very light plastic material of anti-abrasive character.

The device described above operates as follows:

Upon normal operation of the loom, before the arrival of a gripper shuttle 14 into shuttle box 13 at the right side of the loom, the upper free end of control lever 10 is swung out into its extreme right position and is simultaneously placed as near as possible to the guideway 31 of the gripper shuttle l4 inside shuttle box 13 (FIG. 3). This position of control lever 10 is produced by the action of cam 22 of disc 21 and by cam 29 at the bottom of housing 9. At this phase, frictional damper 11 is swung out in such manner that its upper free arm is directed in a direction inclined toward the direction of arrival of the gripper shuttle 14, and is not at this time within the path of the adjusting stop 39, this latter condition is produced later by merely swinging the upper free end of control lever 10 towards guideway 31 inside shuttle box 13.

The gripper shuttle 14 is immediately braked upon its arrival in guideway 31 of shuttle box 13 by a jaw (not shown) opening at the bottom of said guideway 31. The remaining kinetic energy of the shuttle is damped by impact against the front of its edge 33 against the upper free arm of frictional damper 1 1, which is turned upon said impact into a position as shown in FIG. 4. An overturnig of the frictional damper 11 is prevented by a suitable construction of the upper end of the control lever 10, which for this purpose has suitable impact surfaces at its end, for the upper free arm of frictional damper 11, etc. In this phase of controlling the gripper shuttle, the positionof control lever 10 has not been changed, and only frictional damper 11 has turned, as has already been mentioned above.

In the following phase of controlling the gripper shuttle 14, the upper free end of control lever 10 begins to move to the left, and entrains therewith frictional damper 11 which, by pressing against the front of edge 33 of gripper shuttle 14 moves the shuttle into a position which is most suitable for introducing a new weft thread into the thread gripping mechanism at its end. The advancement of gripper shuttle 14 is given by the stroke of control lever 10 in that direction and is performed until one end of the upper free arm of frictional damper 11 touches the adjusting stop 38. Simultaneously, the neighboring edge of the same upper free arm of frictional damper 11 stops further advancing of gripper shuttle 14 into said required position. The said motion of the upper free end of control lever 10 is produced by cam 22 of disc 21 at the bottom of housing 9.

Because this motion of control lever 10 is a positive one, it is checked at that phase, whether gripper shuttle 14 has arrived at all in shuttle box 13, and whether it has arrived slowly, or was not stopped e.g. at the beginning of guideway 31 inside shuttle box 13. Upon the correct arrival of gripper shuttle 14 into shuttle box 13, as described above, frictional damper 11 is turned. In

that case also, its lower free arm is turned, and as soon as the whole frictional damper 11 is displaced in the manner described above, the said lower free arm of frictional damper 11 moves to pass above the tie rod 36 of flag 35 of stop motion mechanism 12, without engaging it. In such case, said mechanism 12 is not energized and gives no impulse for stopping the loom.

In the case wherein the frictional damper I1 is not turned because of failure of gripper shuttle 14 to arrive in shuttle box 13, the lower free arm of frictional damper 11 engages and moves the tie rod 36 of flag 35 of stop motion mechanism 12, thus generating an electric impulse for stopping the loom.

In a further phase of controlling the gripper shuttle 14 according to the present invention, the control lever is swung by cam 29, together with the frictional damper 11, from the guideway 31 in the shuttle box 13 and thus also from the adjusted gripper shuttle 14. At that time or immediately afterwards, through the intermediary of shuttle box 13, the shuttle begins to turn through an angle of 180 with the newly introduced weft thread in its gripping mechanism.

After that swinging, the control lever 10 begins immediately to move forward, i.e. to the right from its basic position. By the said swing motion of control lever 10 from the guideway 31 in shuttle box 13, the upper free arm of frictional damper 11 is situated between the two adjusting stops 38 and 39. Upon this movement of control lever 10 to the right, the upper free arm of frictional damper 11 contact the shorter adjusting stop 39, whereupon the whole frictional damper 11 is turned into the position shown in FIG. 3. At the end of this stroke, control lever 10 engages the spring loaded tie rod 34 of trigger mechanism 16 of ejecting device the piston rod 32 then ejects gripper shuttle 14 into the shed, said gripper shuttle having meanwhile been turned through an angle of 180.

At the end of the above described phase, control lever 10 is displaced towards the guideway 31 of gripper shuttle 14 in shuttle box 13 and together with frictional damper 11 resumes its initial position, which was described at the beginning of the specification, ready for the next reception of the shuttle.

The possible wearing of the edge of the upper arm of the frictional damper 11 due to a large number of impacts of the front of edge 33 of gripper shuttle 14 has no effect upon the adjustment of gripper shuttle 14 into a position which is suitable for introducing a new weft thread into its gripping mechanism.

The said upper arm of frictional damper 11 damps the impact of the front of edge 33 of gripper shuttle 14 at the time at which it is at an inclined position with respect to the direction of arrival of gripper shuttle 14. The point of impact A (FIG. 3) is thus shifted higher towards the end of the upper free arm of frictional damper 11. When gripper shuttle 14 is moved back into its required position, this is effected by the direct action of the same arm of frictional damper 11 but at another contact point B or surface of that arm of the frictional damper 11, respectively. After the impact of the front of edge 33 of gripper shuttle 14 against the upper free arm of frictional damper 11, said frictional damper is turned, as shown in FIG. 4, and thus the point of contact of the damper and the shuttle is shifted a little lower on the upper free arm of frictional damper, i.e. nearer its center of rotation. At that point or surface of contact B there are no high impacts or pressures, and thus the upper free arm of frictional damper 11 does not undergo any substantial wear at such point B.

The operation of the device according to the present invention is repeated in cycles on both sides of the weaving loom.

As can be seen from the above, the device according to the present invention is simple in construction and thus reduces the movable mass to a minimum extent thereby permitting the speed of operation of the loom to be increased.

Although the invention is illustrated and described with reference to one preferred embodiment thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a preferred embodiment, but is capable of numerous modifications within the scope of the appended claims What is claimed is:

1. A device for controlling gripper shuttles in a loom having a rotary shuttle box at one side of the loom, the shuttle box having a shuttle-receiving guideway disposed parallel to the warp shed, comprising a control lever cooperating with the shuttle box, means mounting the control lever for swinging in both the perpendicular and longitudinal plane relative to the guideway of the shuttle box, two adjustable stops of unequal length extending parallel to the axis of rotation of the shuttle box and spaced in a direction transverse to said axis of rotation of the shuttle box, the stops being located at such distances from the shuttle box as to permit the shuttle when in the shuttle box to pass by them, a two-arm frictional damper permanently mounted upon the free end of the control lever, one arm of the damper bing provided with a surface for receiving and adjusting the position longitudinally of the shuttle receiving guideway a gripper shuttle which has arrived in shuttle box, a mechanism for stopping the loom upon the incorrect arrival of a shuttle in the shuttle box, the other arm of the damper forming a feeler for said loom stopping mechanism.

2. A device as claimed in claim 1, wherein the frictional damper is made in a form of a bell-crank, and the bell-crank is pivotally mounted upon the free end of the control lever at a location substantially at the junction of the two arms of the bell-crank.

3. A device as claimed in claim 1, comprising a holder upon which the adjustable stops are mounted, and means mounting the holder upon the shuttle box for adjusting in a direction transverse to the axis of rotation of the shuttle box. 

1. A device for controlling gripper shuttles in a loom having a rotary shuttle box at one side of the loom, the shuttle box having a shuttle-receiving guideway disposed parallel to the warp shed, comprising a control lever cooperating with the shuttle box, means mounting the control lever for swinging in both the perpendicular and longitudinal plane relative to the guideway of the shuttle box, two adjustable stops of unequal length extending parallel to the axis of rotation of the shuttle box and spaced in a direction transverse to said axis of rotation of the shuttle box, the stops being located at such distances from the shuttle box as to permit the shuttle when in the shuttle box to pass by them, a two-arm frictional damper permanently mounted upon the free end of the control lever, one arm of the damper bing provided with a surface for receiving and adjusting the position longitudinally of the shuttle receiving guideway a gripper shuttle which has arrived in shuttle box, a mechanism for stopping the loom upon the incorrect arrival of a shuttle in the shuttle box, the other arm of the damper forming a feeler for said loom stopping mechanism.
 2. A device as claimed in claim 1, wherein the frictional damper is made in a form of a bell-crank, and the bell-crank is pivotally mounted upon the free end of the control lever at a location substantially at the junction of the two arms of the bell-crank.
 3. A device as claimed in claim 1, comprising a holder upon which the adjustable stops are mounted, and means mounting the holder upon the shuttle box for adjusting in a direction transverse to the axis of rotation of the shuttle box. 